Police find bodies of Miss Honduras, sister after kidnapping

Police have found the bodies of the reigning Miss Honduras and her sister dumped beside a river, and said they are holding the sister's boyfriend on suspicion of killing them.

Maria Jose Alvarado, who had planned to fly to London today to compete in the Miss World contest, disappeared with her sister Sofia Trinidad in northwestern Honduras last Thursday after a party, sparking an exhaustive search.

Chief detective Leandro Osorio said the bodies of the 19-year-old beauty queen and her sister had been found partially buried along the banks of the Aguagual River in the town of Arada.

"We are 100 percent sure that it's them," he said.

Maria Jose Alvarado (AAP)

Police have detained Trinidad's boyfriend, arrested Tuesday in connection with the sisters' kidnapping, on suspicion of killing them, Osorio said.

"We are holding the author of this horrific act, Mr Plutarco Ruiz. We have found the murder weapon and the vehicle used to transport them," he said.

Police are investigating additional suspects who they believe played a role in trying to cover up the crime, Osorio added.

Organizers of the Miss World pageant issued a statement Wednesday expressing their condolences, and announcing a tribute this weekend in honor of the slain sisters.

"We are devastated by this terrible loss of two young women, who were so full of life. Our thoughts and prayers are with the family and friends of Maria Jose Alvarado & Sofia Trinidad at this time of grief," the London-based organizers said.

Maria Jose Alvarado is crowned Miss Honduras. (Getty) (Getty)

"We are receiving messages of condolences and support from our Miss World family across the world, who all share our sadness at such a tragedy," the statement added.

"We will be holding a special service with all of the Miss World contestants on Sunday, where we will be honoring the lives of Maria Jose Alvarado and Sofia Trinidad, and say prayers for them and their family."

The pageant organizers said they also planned donate money to a children's home in Honduras in the two women's memory.

Alvarado and Trinidad disappeared outside the northwestern city of Santa Barbara after attending a birthday party for Ruiz at a local resort.

Osorio said forensics investigators had not yet examined the bodies, but that evidence indicated the women were killed the same night.

Police arrested Ruiz on Tuesday, seizing a Colt .45 pistol and two vehicles.

"Investigators have been working tirelessly to get to the bottom of these atrocious acts, which have caused mourning in Santa Barbara and across Honduras," Osorio said.

The sisters were last seen leaving the party in a champagne-colored car.

Their mother, Teresa Munoz, says the same vehicle arrived at her home earlier that day to pick up Maria Jose, who had just arrived from the capital Tegucigalpa, about 200km away.

Sofia was supposedly inside the car at the time, but Munoz said she did not see her.

"It seemed strange to me that Sofia didn't get out of the car. I asked Maria Jose why and she said they were in a hurry, and left," she said.

Alvarado had been set to fly to London on Wednesday to compete in Miss World, which begins Saturday and wraps up on December 14.

She was also known in Honduras for her work as a model on a popular TV game show called "X-0."

Her family had made a tearful plea for the sisters' safe return after their disappearance.

Residents of Santa Barbara held a demonstration demanding their release Tuesday, when hope still lingered that they were alive. Wearing white T-shirts with the girls' pictures on them, they marched with a banner reading "May God protect them."

Honduras, a poor Central American country of eight million people, has the world's highest homicide rate: 90.4 per 100,000 inhabitants.

The United Nations' special rapporteur on violence against women, Rashida Manjoo, warned in July that violence against women was on the rise in Honduras, with a 263.4-percent increase in the number of women killed violently between 2005 and 2013.